The present invention is directed to fluid containers or dispensers, and in particular to graduated burettes. More specifically, the present invention provides a novel assembly for feeding fluid to a container or dispenser, which assembly also automatically adjusts the level of fluid in the container or dispenser to a predetermined level. In this regard reference is made to U.S. Pat. Nos. 2,158,102; 1,993,001; 3,145,876; and 844,686 which comprehensively describe the feeding and automatic leveling apparatus which are available in the burette art.
The available prior art self-leveling burette assemblies have many drawbacks. The prior art assemblies generally comprise a separate fluid reservoir, aspirator bulb and overflow tubing, thus rendering rather cumbersome assemblies. The rigid glass parts of the prior art assemblies are fragile and are generally not replaceable. Since the fluid reservoir is fixidly positioned to a rigid feeding tube, removal of the reservoir for filling of the same is difficult. Generally speaking, the prior art assemblies use intricate plumbing systems to perform the burette filling and self-leveling functions, thus rendering systems of substantial weight and complexity. Furthermore, such intricate plumbing systems generally utilize numerous valves and petcocks, thus presenting a substantial maintenance requirement for the systems. The prior art assemblies generally cannot be transported without first emptying the fluid from the reservoir. Also, if a liquid is stored in a prior art glass reservoir and is frozen, the reservior will break. Generally speaking, the various parts of the prior art assemblies are packaged and shipped separately and must be assembled before use.